New Materials Boost Efficiency and Stability of Optical Rectennas

Rectennas convert electromagnetic fields at optical frequencies directly to electrical current. Optical rectennas operate by coupling light’s electromagnetic field to an antenna. The electromagnetic field creates an oscillation in the antenna, producing an alternating flow of electrons. When the electron flow reaches a peak at one end of the antenna, the diode closes, trapping the electrons, then re-opens to capture the next oscillation, creating a current flow. This switching must occur at terahertz frequencies to match the light. The junction between the antenna and diode must provide minimal resistance to electrons flowing through it while open, yet prevent leakage while closed.